I don't understand

run_rule_with_mocks

enough. I have 2 field sets i"m testing with

run_test

. If I omit the

MockGet(RunRequest, SecondFieldSetType)

it runs but complains about not being able to satisfy the request. If I add it I get

ValueError

about the

Get

providers. Not sure what I'm doing wrong.

Is your example intended to be accurate? It has no 3rd argument - the actual mock callable: https://github.com/pantsbuild/pants/blob/2168bb3b0a5074e4f69644fa78df60f4ed3098be/src/python/pants/testutil/rule_runner.py#L522-L528

Ahhhhh found it, looks like the previous authors were lazy and left off

union_membership